Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation

IntroductionThe retinoblastoma protein (pRb) is a key regulator of the cell cycle that suppresses cell proliferation by binding to E2F transcription factors. Disruption of this pathway, commonly through mutations or interactions with viral oncoproteins, can lead to uncontrolled cell growth and cance...

Full description

Saved in:
Bibliographic Details
Main Authors: Carla Luciana Padilla Franzotti, Nicolas Palopoli, Juliana Palma, Gustavo Pierdominici-Sottile
Format: Article
Language:English
Published: Frontiers Media S.A. 2025-04-01
Series:Frontiers in Chemical Biology
Subjects:
Online Access:https://www.frontiersin.org/articles/10.3389/fchbi.2025.1538350/full
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850201217855127552
author Carla Luciana Padilla Franzotti
Carla Luciana Padilla Franzotti
Nicolas Palopoli
Nicolas Palopoli
Juliana Palma
Juliana Palma
Gustavo Pierdominici-Sottile
Gustavo Pierdominici-Sottile
author_facet Carla Luciana Padilla Franzotti
Carla Luciana Padilla Franzotti
Nicolas Palopoli
Nicolas Palopoli
Juliana Palma
Juliana Palma
Gustavo Pierdominici-Sottile
Gustavo Pierdominici-Sottile
author_sort Carla Luciana Padilla Franzotti
collection DOAJ
description IntroductionThe retinoblastoma protein (pRb) is a key regulator of the cell cycle that suppresses cell proliferation by binding to E2F transcription factors. Disruption of this pathway, commonly through mutations or interactions with viral oncoproteins, can lead to uncontrolled cell growth and cancer. The large T antigen of simian virus 40 (LTSV40) is known to bind pRb, thereby inhibiting its interaction with E2F transcription factors. However, the structural and dynamic mechanisms underlying this inhibition remain incompletely understood.MethodsWe employed molecular dynamics (MD) simulations, principal component analysis, and cluster analysis to investigate the conformational dynamics of pRb, LTSV40, and their complex. Our study focused on an intrinsically disordered region on the C-terminal side of the LFCSE motif of LTSV40, referred to as Linker 1.ResultsOur simulations reveal that Linker 1 undergoes a significant conformational shift upon binding to pRb. While this region adopts a predominantly bent structure in the unbound state, it transitions into an extended conformation in the complex. As a consequence of this change, the C-terminal segment of LTSV40 obstructs access to the AB-cleft of pRb, the binding site for E2F.DiscussionOur findings suggest that the inactivation mechanism of pRb by LTSV40, as unveiled by MD simulations, could represent a broader strategy employed by other viral oncoproteins containing similar LXCXE motifs and adjacent disordered regions. This mechanism may even extend to endogenous pRb inactivation. As our conclusions are based on computational modeling, they require experimental validation. Such confirmation would pave the way for developing therapeutic strategies aimed at reactivating pRb function in pathologies where it is compromised.
format Article
id doaj-art-121905a8f06f49b8bf83638918f8ba64
institution OA Journals
issn 2813-530X
language English
publishDate 2025-04-01
publisher Frontiers Media S.A.
record_format Article
series Frontiers in Chemical Biology
spelling doaj-art-121905a8f06f49b8bf83638918f8ba642025-08-20T02:12:06ZengFrontiers Media S.A.Frontiers in Chemical Biology2813-530X2025-04-01410.3389/fchbi.2025.15383501538350Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivationCarla Luciana Padilla Franzotti0Carla Luciana Padilla Franzotti1Nicolas Palopoli2Nicolas Palopoli3Juliana Palma4Juliana Palma5Gustavo Pierdominici-Sottile6Gustavo Pierdominici-Sottile7Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, ArgentinaConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires (CABA), Buenos Aires, ArgentinaDepartamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, ArgentinaConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires (CABA), Buenos Aires, ArgentinaDepartamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, ArgentinaConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires (CABA), Buenos Aires, ArgentinaDepartamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Buenos Aires, ArgentinaConsejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Ciudad Autónoma de Buenos Aires (CABA), Buenos Aires, ArgentinaIntroductionThe retinoblastoma protein (pRb) is a key regulator of the cell cycle that suppresses cell proliferation by binding to E2F transcription factors. Disruption of this pathway, commonly through mutations or interactions with viral oncoproteins, can lead to uncontrolled cell growth and cancer. The large T antigen of simian virus 40 (LTSV40) is known to bind pRb, thereby inhibiting its interaction with E2F transcription factors. However, the structural and dynamic mechanisms underlying this inhibition remain incompletely understood.MethodsWe employed molecular dynamics (MD) simulations, principal component analysis, and cluster analysis to investigate the conformational dynamics of pRb, LTSV40, and their complex. Our study focused on an intrinsically disordered region on the C-terminal side of the LFCSE motif of LTSV40, referred to as Linker 1.ResultsOur simulations reveal that Linker 1 undergoes a significant conformational shift upon binding to pRb. While this region adopts a predominantly bent structure in the unbound state, it transitions into an extended conformation in the complex. As a consequence of this change, the C-terminal segment of LTSV40 obstructs access to the AB-cleft of pRb, the binding site for E2F.DiscussionOur findings suggest that the inactivation mechanism of pRb by LTSV40, as unveiled by MD simulations, could represent a broader strategy employed by other viral oncoproteins containing similar LXCXE motifs and adjacent disordered regions. This mechanism may even extend to endogenous pRb inactivation. As our conclusions are based on computational modeling, they require experimental validation. Such confirmation would pave the way for developing therapeutic strategies aimed at reactivating pRb function in pathologies where it is compromised.https://www.frontiersin.org/articles/10.3389/fchbi.2025.1538350/fullpRbE2FLTSV40retinoblastoma proteinviral oncoproteinsMD simulations
spellingShingle Carla Luciana Padilla Franzotti
Carla Luciana Padilla Franzotti
Nicolas Palopoli
Nicolas Palopoli
Juliana Palma
Juliana Palma
Gustavo Pierdominici-Sottile
Gustavo Pierdominici-Sottile
Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
Frontiers in Chemical Biology
pRb
E2F
LTSV40
retinoblastoma protein
viral oncoproteins
MD simulations
title Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
title_full Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
title_fullStr Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
title_full_unstemmed Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
title_short Structural and dynamical characterization of pRb, LTSV40 and the pRb-LTSV40 complex suggests a common mechanism for pRb inactivation
title_sort structural and dynamical characterization of prb ltsv40 and the prb ltsv40 complex suggests a common mechanism for prb inactivation
topic pRb
E2F
LTSV40
retinoblastoma protein
viral oncoproteins
MD simulations
url https://www.frontiersin.org/articles/10.3389/fchbi.2025.1538350/full
work_keys_str_mv AT carlalucianapadillafranzotti structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT carlalucianapadillafranzotti structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT nicolaspalopoli structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT nicolaspalopoli structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT julianapalma structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT julianapalma structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT gustavopierdominicisottile structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation
AT gustavopierdominicisottile structuralanddynamicalcharacterizationofprbltsv40andtheprbltsv40complexsuggestsacommonmechanismforprbinactivation